The near field properties of colloidal polystyrene microspheres on silicon

We have investigated the optical resonance and near field inside and under absorptive polystyrene (PS) microspheres on Si wafers. Near field flat plane images of PS microspheres were numerically simulated. Nanostructures were prepared on Si substrates using the regular two dimensional (2D) arrays by a single pulsed laser irradiation (KrF, lambda = 248 nm). Periodical PS nanoparticle, PS nanoflowers and Si nanobumps were fabricated by different laser fluence. Mechanisms for PS particle size reduction and Si nanobump formation by laser irradiation were discussed on the base of the theoretical calculations. Good agreement between theoretical calculations and experimental results has been observed.